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First issue with the Thumper

PostPosted: Wed Mar 28, 2012 10:15 pm
by ColoradoKid
So, was at the range yesterday and my bolt carrier got stuck at a position just a fraction of an inch before the round. Pulled the trigger and click, no bang. So i dropped the mag and and wracked back the carrier and the round didnt eject. So i wracked her forward again and it got stuck in the same position again, but this time stuck stuck. Finally gave it a REALLY good yank and the carrier came back and this time ejected the round. Worked fine after I cleared the jam, but it does have me a little concerned. Any idea as to what might cause this?

Nothing appears to be out of place, but i have had an occasional stove pipe due to some issue with the ejection pin.

Re: First issue with the Thumper

PostPosted: Wed Mar 28, 2012 11:30 pm
by Texas Sheepdawg
Sounds like grit, carbon or dirt or powder buildup on the bolt or in the lockup area of the chamber. Maybe time to disassemble the bolt and give it a good cleaning and also the lockup area of the chamber?

Re: First issue with the Thumper

PostPosted: Thu Mar 29, 2012 4:07 am
by Hoot
Give the extractor and ejector on the bolt a good look, both for odd scraping (extractor) and function (both). Look closely, at the bolt lugs and barrel extension lugs for signs of an unintended collision. Otherwise, clean the crap out of everything. Everyone encounters the rare, mysterious hang-up. It's only when that becomes less random, that you need to be concerned. Post a focused pic of the case head and rim if you still have it segregated from the other spent cases. Ditto on any signs of the aforementioned unexpected collision. We love to mull over pics as they speak volumes and in a universal language. ;)

Hoot

Re: First issue with the Thumper

PostPosted: Thu Mar 29, 2012 6:58 am
by bushmeister
Clean that little channel where the charging handle slides as well as what they said, sometimes debris can get in there.

Re: First issue with the Thumper

PostPosted: Thu Mar 29, 2012 8:23 am
by ColoradoKid
Thanks for the suggestions! I just cleaned her about 20 rounds ago, but I do admit that I may need to pay a little more attention to detail during cleaning.

Looking for recommendations on cleaning preferences.

I've been using a bore snake after range time between cleanings. When it comes down to a real cleaning I use bore tech eliminator in the bore and hoppe's 9 on all the action parts. Scrubbed with a nylon brush then a wire brush for those stubborn areas.

Should probably soak the bolt/carrier, but need to know which solvent is best for doing so? What oil and on what parts? What tools for cleaning the chamber? I've watched numerous "ar15 cleaning" videos and all of them seem to vary slightly.

How do you guys roll?

Re: First issue with the Thumper

PostPosted: Thu Mar 29, 2012 9:46 am
by gunnut
pay special attention to the locking lugs in the barrel extention and bolt. Difficult to clean properly.

Re: First issue with the Thumper

PostPosted: Thu Mar 29, 2012 10:42 am
by wildcatter
All of the above, but the most prevelent problems can be laid at the feat of cleaning/lubing and MUST be done before the first range day.

So, make youtube your best friend..

..t

in three parts.. http://www.youtube.com/watch?v=eSpBJSgCvqg

Re: First issue with the Thumper

PostPosted: Thu Mar 29, 2012 4:16 pm
by BillytheKid
Did the brass show any signs of being dented or malformed?

Just a thought.

Re: First issue with the Thumper

PostPosted: Thu Mar 29, 2012 7:34 pm
by helidude350
Also check your magazines and inspect the rounds new from the box.
I have found issues with both.
I have found a few rounds with defects straight from the box.
I have also had some issues with mags too full, making the second round ( which should really be the first)
dragging on the bottom of the bolt carrier.
I have also had the rounds riding too high, nose up, or rim up
and cause a jam.

Re: First issue with the Thumper

PostPosted: Thu Mar 29, 2012 8:42 pm
by firehawk
helidude350 wrote:I have also had some issues with mags too full, making the second round ( which should really be the first)
dragging on the bottom of the bolt carrier.
I have also had the rounds riding too high, nose up, or rim up
and cause a jam.


The exact problem I experienced with my modified 30 round Pmag first time out, rounds nose up. Problem was solved with removing 3 coils from the magazine spring. Too much spring pressure was causing the second round to be dragged along with the first when loaded with 10 rounds.

.02